Soil excavating apparatus



Nov. 9, 1965 M. P. WALKER 3,216,589

SOIL EXCAVATING APPARATUS Filed March 6, 1964 AM /EN n18 flmrmzu/ Far /v mu kE/E United States Patent Ofiice 3,216,589 Patented Nov. 9, 1965 3,216,589 SOIL EXCAVATING APPARATUS Matthew Paton Walker, Long Load, Langport, Somerset, England Filed lldar. 6, 1964, Ser. No. 349,933 Claims priority, application Great Britain, Apr. 8, 1963, 13,872/63 1 Claim. (Cl. 21268) The present invention relates to soil excavating apparatus and in particular concerns improvements in or modifications of the apparatus described in my previous Patent No. 2,880,894 (British Patent No. 785,585).

The invention described in said Patent No. 785,585 is concerned with soil excavating apparatus of the type including a boom pivoted to a supporting structure mounted on or adapted to be mounted on a tractor so as to be raised and lowered by a hydraulically operated boom ram about a substantially horizontal axis, and carrying at its outer end a dipper arm pivoted on the boom for movement through the medium of a dipper rarn, said dipper arm supporting a scoop tiltably mounted at the arms outer end and adapted to be tilted with respect to the dipper arm by another hydraulic ram usually referred to as the crown ram; all the rams have fluid connections adapting them to be powered by pressure fluid supplied from the tractor, and the boom is constructed for slewing on a substantially vertical axis about a king post carried on the aforesaid supporting structure. The foregoing is a known kind of excavator apparatus and no claim is made herein to the same per se; it is hereinafter referred to as the type described.

The primary object of the present invention is to impart a more powerful and smoother movement to effect a correspondingly more powerful and smoother transmission to the king post.

According to the present invention, a soil excavating apparatus of the type described is characterised in that a toothed gear (herein the first gear) is mounted on the supporting structure and meshes with a toothed gear on the king post, and is oscillatable by two hydraulic slewing rams working simultaneously, each ram being connected by one end directly to said first gear at a point angularly spaced from that of the other, and by its other end to a part of the supporting structure, the parts being located on opposite sides of the longitudinal centre line of the apparatus, whereby one ram imparts a pushing force and the other at the same time a pulling force to the said first gear so that one ram supplements the action of the other.

In order that the said invention may be readily understood an embodiment thereof will be described by way of example with the aid of the accompanying drawings in which:

FIGURE 1 is a diagram depicting a side elevation of the kind of excavating apparatus to which the invention is applicable;

FIGURE 2 is an enlarged plan view of part of the supporting structure showing the king post and gearing thereof according to the present invention; and

FIGURE 3 is a side elevation of FIGURE 2.

Like numerals of reference indicate the same or corresponding parts in the several views.

FIGURE 1 shows the excavating apparatus in full lines attached to a bull-dozing tractor depicted in broken (dash) lines.

The excavating apparatus includes a supporting structure in the form of a yoke which is adapted to be pivoted to the rear of a tractor near the base of the chassis framework thereof or to any other convenient fixed structure. This yoke takes the form of a substantially V-shaped framework 1 lying apex outwards away from the point of attachment to the tractor of a pair of parallel arms 2, 2 extending respectively from the tips of the legs of the V 1 and adapted to lie one on each side of the tractor. These arms are furnished with eyed ends 3 adapting them to be pivoted to the tractor, as already stated, so that the yoke may be swung up from a normal working position in the horizontal out of action position through an angle of approximately 45. The pivotal movement also enables the yoke to be swung downward to a limited degree and also upward through any requisite small angle to secure that the supporting structure 1, 2 is substantially horizontal even though the tractor may be sited on a slope leading down or up from the area of excavation. The rise and fall of the yoke is brought about by a pair of hydraulic rams 4 extending downwardly from side uprights 5 fixed to the tractor at or about the pivotal axis of the structure 1, 2, and pivotally secured to the structure one at each side at or about the junction of the legs of the V element 1 with the arms 2 of the supporting structure.

At the apex 1a of the said V structure 1 there is erected a king post 7 supported at the top by a horizontal arm 8 projecting forwardly (i.e. away from the tractor and the pivotal ends 3 of the structure 1, 2) from an A-frame 9 or similar structure also erected from the supporting structure 1, 2 further back than the king post, i.e. nearer to the tractor. In the normal working position the king post 7 stands substantially vertically and it is rotatably mounted between the said horizontal arm 8 at the top and the structure 1, 2 at the bottom in suitable bushings and bearings. The king post 7 carries the boom which is conveniently in the form of a pair of parallel triangular plates 10, 10 spaced apart and secured together and pivoted by one of the pairs of angular corners at 11 to a pair of lugs 12 projecting from the king post 7 near the bottom thereof. Thus the boom 10, 10 can be raised and lowered about this horizontal boom pivot at 11. The outer end 13 of the boom (another angular corner of the triangular platework 10) is linked to the king post 7 by the boom ram 14. For this purpose the post 7 is furnished with an upper lug arrangement 15, at or near its top, projecting over the aforesaid lower lugs 12 to which the boom is pivoted. The upper lug ar rangement 15 projects outwardly and upwardly with its top approximately above the king post 7.

It will be appreciated that the boom is slewed by rotating the king post 7, and inasmuch as the vertical axis of turning is carried by the tip 1a of the supporting structure 1, 2 well clear of the tractor the boom can be swung backwards towards the tractor through an angle much more than a right-angle on each side of the king post.

As usual with excavating apparatus of the type described, a dipper arm 20 is mounted on the outer end of the boom 10. This is in the form of a two-armed lever pivoted to the boom at 21 the lever having a long arm carrying the scoop 22 pivoted at the end of the arm and a short arm connected to the boom by a dipper ram 23. The scoop 22 is linked, as usual, to a double-plate 24 pivoted to the top of the dipper arm 20 and controlled by a crown ram 25 lying along the dipper arm and mounted between the said double-plate 24 and the arm.

The various rams are connected by flexible piping (not shown) to suitable valve controls on the tractor through which the ram-actuating pressure fluid passes.

As described so far the embodiment conforms generally with structure common to my prior US. Patent No. 2,880,894.

According to the illustrated embodiment of the present invention the means for producing slewing of the boom 10, 10 is as follows, referring to FIGURES 2 and 3. The king post 7 (which, as explained, carries the lugs 12 to which the boom is pivoted) is rotatably mounted on the apex 1a of the yoke-shape supporting structure of which the V legs 1, 1 and part of the parallel arms 2, 2 are shown. The post 9 of theA-frame which is parallel to the king post 7 is fixedly erected from the supporting structure.

The V part 1 of the yoke supporting structure is a duplicated member having similar upper and lower parts which are superimposed as seen in FIGURE 3. The two parts of the V structure 1 would be connected together around their edges by cover plates to form a protective sheathing. Such plates are omitted so as to expose gearing hereinafter described.

Fixed to the king post 7 so as torotate therewith and disposed between the upper and lower parts of the supporting structure is a pair of similar gear wheels 17, 17 which are in mesh respectively with a pair of gears 18, 18 in the form of quadrants. The gearing is protected by being enclosed between the upper and lower parts of the supporting structure. The two gears 17 work in unison by being fixedly mounted on that part of the shaft 7 which rotates between the parts 1 of the yoke structure. The quadrants 18, 18 rotate on the fixed post 9 and also work in unison by being fixed to a common sleeve 19 rotatable on the post 9 and are also connected together by pins 26.

The combined quadrant 18, 18 by meshing with the gear wheels 17, 17 can rotate the king post 7 and thus slew the boom 10, 10. The amount of rotation of the gears 17 (and hence the king post 7) given by the quadrants 18 will obviously depend on the gear ratio therebetween. The method of turning the composite quadrant member 18 is by means of two slewing rams 27, each of which is connected by one end directly to a respective pin 26 of the quadrant assembly 18, these pins 26 being angularly spaced apart. The other ends 28 of the slewing rams 27 are pivotally connected to the supporting structure at opposite sides of the longitudinal centre line of the apparatus which, in the drawings, is a horizontal line passing through the centres of the post 9 and king post 7. The slewing rams 27 work simultaneously so that, according to the direction of slewing one ram imparts a pushing force and the other a pulling force to the gear consisting of the quadrants 18, 18, and thus each ram supplements the action of the other.

I claim:

In a soil excavating apparatus comprising a boom fast on an upright king post mounted for turning on its axis at the apex of a V-framework constructed with two main bars which extend at right angles to the axis of the king post and which converge towards said axis and are symmetrical about a vertical plane containing said axis, the provision of a toothed gear wheel which is fast on and coaxial with the king post, a toothed gear quadrant meshing with said gear Wheel and mounted on the framework for turning on an axis which is parallel to the axis of the gear wheel, and two hydraulic rams symmetrically mounted one on each side of said plane with their axes convergent, a pivotal attachment of one end of one hydraulic ram to one of said bars and a pivotal attachment of the other end of said one hydraulic ram to the gear quadrant on the same side of said plane as said one of said bars, a pivotal attachment of one end of the other hydraulic ram to the other of said bars and a pivotal attachment of the other end of said other hydraulic ram to the gear quadrant on the opposite side of said plane, and the pivotal axis of each of said pivotal attachments being parallel to the axis of the gear wheel.

References Cited by the Examiner UNITED STATES PATENTS 1,791,667 2/31 Foley 2l268 2,404,639 7/46 Lane.

2,796,998 6/57 Sundin 21266 2,880,894 4/59 Walker 214-138 2,903,142 9/59 Wills 212-66 HUGO O. SCHULZ, Primary Examiner. 

